Technical Field
This application relates to the design of jet engine mounting pylons, or struts, that provide enhanced aerodynamic and fuel consumption performance.
Related Art
Most of today's commercial jet airliners are powered by high-bypass turbofan jet engines. The exhaust of these engines is divided into two concentric “zones,” viz., an outer, relatively high-rate-of-flow, low-velocity-and-temperature, “fan exhaust” zone, and an inner, relatively low-rate-of-flow, high-velocity-and-temperature, “core exhaust” zone.
The mounting pylon of each engine couples the engine to the aircraft's wing and typically comprises a structural component, or “strut,” encased within a streamlining skin, or “fairing.” It is typically located at least partially within the “Hot-Zone,” i.e., the core exhaust, of the associated engine, which necessitates the presence of heat shields over the strut in this area to prevent heat degradation of the strut. Further, since air speeds in the core exhaust area are supersonic, the resulting parasitic drag imposed on the strut in this zone is relatively severe. Along with increased drag, there is additional mass associated with both the heat shields needed to insulate the wing from the hot core exhaust gases, as well as the extended aft fairings of the strut.
Accordingly, there is a long felt but as yet unsatisfied need in the industry for jet engine mounting strut designs that eliminate the requirement for strut exhaust shields in the core exhaust nozzle zone, and which reduce the drag and attendant fuel consumption associated with the strut aft fairings.